diff --git a/src/calendar.cpp b/src/calendar.cpp
index d3c7ec65877fa..464a0fd53a3e3 100644
--- a/src/calendar.cpp
+++ b/src/calendar.cpp
@@ -553,7 +553,7 @@ std::string to_string( const time_point &p )
         //~ 1 is the year, 2 is the day (of the *year*), 3 is the time of the day in its usual format
         return string_format( _( "Year %1$d, day %2$d %3$s" ), year, day, time );
     } else {
-        const int day = day_of_season<int>( p );
+        const int day = day_of_season<int>( p ) + 1;
         //~ 1 is the year, 2 is the season name, 3 is the day (of the season), 4 is the time of the day in its usual format
         return string_format( _( "Year %1$d, %2$s, day %3$d %4$s" ), year,
                               calendar::name_season( season_of_year( p ) ), day, time );
diff --git a/tests/stats_tracker_test.cpp b/tests/stats_tracker_test.cpp
index 6f549a2708134..267215098ae12 100644
--- a/tests/stats_tracker_test.cpp
+++ b/tests/stats_tracker_test.cpp
@@ -273,16 +273,16 @@ TEST_CASE( "achievments_tracker", "[stats]" )
         if( time_since_game_start < 1_minutes ) {
             CHECK( a.ui_text_for( achievements_completed.at( a_kill_zombie ) ) ==
                    "<color_c_light_green>One down, billions to go…</color>\n"
-                   "  <color_c_light_green>Completed Year 1, Spring, day 0 0000.30</color>\n"
+                   "  <color_c_light_green>Completed Year 1, Spring, day 1 0000.30</color>\n"
                    "  <color_c_green>1/1 Number of zombies killed</color>\n" );
             CHECK( a.ui_text_for( achievements_completed.at( a_kill_in_first_minute ) ) ==
                    "<color_c_light_green>Rude awakening</color>\n"
-                   "  <color_c_light_green>Completed Year 1, Spring, day 0 0000.30</color>\n"
+                   "  <color_c_light_green>Completed Year 1, Spring, day 1 0000.30</color>\n"
                    "  <color_c_green>1/1 Number of monsters killed</color>\n" );
         } else {
             CHECK( a.ui_text_for( achievements_completed.at( a_kill_zombie ) ) ==
                    "<color_c_light_green>One down, billions to go…</color>\n"
-                   "  <color_c_light_green>Completed Year 1, Spring, day 0 0010.00</color>\n"
+                   "  <color_c_light_green>Completed Year 1, Spring, day 1 0010.00</color>\n"
                    "  <color_c_green>1/1 Number of zombies killed</color>\n" );
             CHECK( !achievements_completed.count( a_kill_in_first_minute ) );
             CHECK( a.ui_text_for( &*a_kill_in_first_minute ) ==